Towing Vehicles in the States

Bob Eustace

Whether or not your tow vehicle is up to the task really depends on your particular circumstances and where you will be traveling (towing numbers are a little farther below).  But a couple of things that you should do regardless are to get a transmission cooler (if you have an automatic), and check the size of your alternator.

I would recommend *at least* a 90 amp alternator to be safe, but would go with 130-140 amps in you could.  If the alternator can not supply enough power to run all the vehicle lights/widgets, and the trailer lights (trailer running, brake, turn signals, etc.); then the vehicle will begin to pull power from the vehicle battery to supplement what it needs.  In the case of towing a trailer, power will draw from both the car *and* trailer battery since the two are tied together through the 12 volt battery charge wire in the RV plug.  You use more power in a hard rain than a light rain.  Window defrosters & defoggers, seat warmers, auto dimming mirrors, outside temp gauges, heated side mirrors, CD players, cell phones plugged in, map lights, all require power and it all adds up.

Regarding your tow vehicle and numbers:

Not all companies figure tow ratings in the same manner.  US companies normally base their tow rating on: one (1) 150 lb driver in an empty base model tow vehicle, but this can vary.  Other companies may use
other formulas.  Your owners manual may say how it is figured.  Ours says, "Maximum trailer weight is calculated assuming the driver and one passenger are in the tow vehicle and it has all the required
trailer equipment."  If you manual does not give such guidelines, it's best to call the 800 customer service number and see if you can get a clear answer.  The difference in how tow ratings are figured is one reason people argue about tow ratings and what works, doesn't work, etc.

But to get you started:

Using the "Combined" weight figure and the vehicle's curb weight from the sticker on the driver's door, you can work backwards and get a number... We'll start with the numbers you provided.

Gross Combine Weight Rating (maximum of tow vehicle
+ trailer): 6250
Gross Vehicle Weight Rating (maximum loaded weight
of vehicle): 5040

GCWR - GVWR = tow capacity

6250 - 5040 = 1,210

According to the numbers, 1,210 lbs should be the amount that your fully loaded minivan can tow.  It doesn't equal 2,000 lbs.  So your minivan's tow capacity can't be based upon a fully loaded vehicle being capable of towing 2,000 lbs.

We now use the curb weight of the van  GCWR - CW = tow capacity (I'll use an imaginary number here):

6250 - 4000 = 2,250 lb capacity.

This is the total number of lbs in people, cargo, and trailer weight that you have to work with.  With a curb weight of 4,000 lbs, if you purchased an A'liner that weighed in at 1,400 lbs, with a tongue weight of 150 lbs; you could put a total of 700 lbs in the van (this weight includes yourselves).  Say you all weighed 300 lbs combined = 400 lbs cargo in the van.  Tongue weight is considered weight in the van because the is weight is being carried by the hitch and riding on the van's axles.

Also consider that you may be able to remove the third and maybe even the second row seats from the
minivan when travelling.  Weigh the seats.  You can then add this amount back in as cargo or towing capacity if you leave the seats at home.

If you stay within the specs, the vehicle should accelerate and merge with traffic without difficulty *when at sea level*.  If you travel in high altitudes or cross mountains, things will be different.  Figure that for every 1,000 ft of
altitude there is a 3% loss in engine HP.  This is why the "75% Rule" for towing is followed by many people.  The 75% Rule says that the weight of the trailer should not exceed 75% of the vehicle's tow capacity.  This reduction will then give you some performance leeway when climbing mountains etc. Your tow vehicle and trailer will accelerate better, etc.  www.trailerlife.com has several good articles covering these points.

Some weights to keep in mind:
Water = 8.33 lbs per gallon
20 # LP bottle (empty) = 18 lbs
20 # LP bottle (full) = 36 lbs
Dometic 3 cu. ft. fridge = 65 lbs.

Just an FYI, our A'liner LX (loaded with options but no A/C) weighs in at 1,620 lbs without cargo, but with two full propane bottles.  The tongue weight, unloaded, is 180 lbs.  I think we are one of the heavier trailers in the group.

Hitches:

Hitches are rated as Class I, Class II, Class III. Class I = 2,000 lbs towing & 200 lbs tongue weight
limit.  Class II = 3,500 lbs towing &  350 lbs tongue weight.  Class III = 5,000 lbs towing & 500 lbs tongue weight.  Class I or Class II will work for you.

Companies such as "Draw Tight" and "Hidden Hitch" should have hitches that will bolt directly to the vehicles frame and may not require any drilling. Stay away from hitches that mount on the bumper are attached to the floor of the trunk and not the vehicle frame.

You will need to then purchase a "ball mount".  This is the part that slides into the hitch on the car. A properly fitted ball mount should keep the trailer hitch within one inch of being level - with closer to zero being better.  Standard A'liners have a 14" hitch height.  So if your hitch receiver on the vehicle is 12" off the ground, you will need a ball mount with a 2 inch rise.  Our current hitch receiver is at 18" so we have a ball mount with a 4 inch drop.

Hope this help,
Chris